index creation

Hi, Folks

I have got a big table containing huge data, I am trying to create a composite index on three columns, the three columns are varchar2 datatype, but I notice(and confirm) that the data in these columns are numeric. in other words, I may change their datatype to be Numeric, hence, I have got two choices to create index either upon varchar, or Nuerice, can you tell me which way has the better performance to retrive data ?

Any advice will be highly appreciated.

xiongOriginally posted by xli
Hi, Folks

I have got a big table containing huge data, I am trying to create a composite index on three columns, the three columns are varchar2 datatype, but I notice(and confirm) that the data in these columns are numeric. in other words, I may change their datatype to be Numeric, hence, I have got two choices to create index either upon varchar, or Nuerice, can you tell me which way has the better performance to retrive data ?

Any advice will be highly appreciated.

xiong
If all the values in the column are menat to be numeric, then NUMBER is a better choice than VARCHAR2. It will use fewer bytes, and comparisons will be faster.